iiinova — where your digital self keeps evolving

Geoff Wearmouth @warmtoffee.bsky.social · 01/10/2026

Jupiter Ace - the making of a micro

Steve Vickers (left) and Richard Altasser, co-designers of the Jupiter Ace.

Reposted by Geoff Wearmouth

VGC @videogameschronicle.com · 29/09/2026

The clamshell C64 and ZX Spectrum handhelds, which were set for release in two weeks, have been delayed by six months. Manufacturer Blaze says the "product construction was not meeting our high standards". www.videogameschronicle.com/news/the-cla...

videogameschronicle.com

The clamshell C64 and ZX Spectrum handhelds have been delayed by six months because of production quality | VGC

Blaze Entertainment says the handhelds were “not meeting our high standards”…

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Lisa Schiff @crkrjx.bsky.social · 21/09/2026

Between 1949 and 1982, more than 200,000 barrels of low-level radioactive waste (150,000 tons) were dumped into the ocean. Now, scientists have descended to the wreckage to investigate – and found many of the barrels corroded and degraded, their contents spilling across the seafloor.

yahoo.com

150,000 Tons of Radioactive Waste Were Dumped in The Atlantic. Decades Later, It's Visibly Oozing.

Well, well, well. If it isn't consequences.

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Geoff Wearmouth @warmtoffee.bsky.social · 20/09/2026

A utility by Andrew Pennell, who wrote the microdrive demo cartridges, that allows you to check the sectors on the cartridge. No need to type this in itnis downloadable from these good guys. More next month. spectrumcomputing.co.uk/entry/24283

spectrumcomputing.co.uk

Microdrive File Repair - Spectrum Computing

Microdrive File Repair for ZX-Spectrum 48K (?) by Andrew Pennell

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Geoff Wearmouth @warmtoffee.bsky.social · 19/09/2026

I tried Google and Grok and neither of them cautioned against using values above 91 which crashes the ZX Spectrum - the reason I wrote to Sinclair Research early in 1985. After a lukewarm reply I wrote to Popular Computing Weekly, 5th September 1985.

Grok
(note: COPY does not use the printer buffer and should not end by clearing it )

My “New Concept” letter on 5th September 1985

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Geoff Wearmouth @warmtoffee.bsky.social · 19/09/2026

Me too, until I saw this strip from the UK Daily Mirror, July 1952, before Steven was born. His father, general manager of the Pilot Ace arranged press visits and James Hardy Wilkinson officiated. Two influences to the ZX Spectrum manual - the RASP system variable and the first example program

Legend James Hardy Wilkinson explains how the computer makes a sound like a Raspberry and then demonstrates how the computer can find what day reporter Ruggles was born on from the date of birth.

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Reposted by Geoff Wearmouth

Geoff Wearmouth @warmtoffee.bsky.social · 07/09/2025

I get my first two ZX Spectrum programs published in the letters page of Popular Computing Weekly 1985

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Sinclair Research @sinclairresearch.bsky.social · 18/09/2026

No idea how this works. #TGIF

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Geoff Wearmouth @warmtoffee.bsky.social · 17/09/2026

An interesting letter reveals that on a ZX Spectrum playing Scrabble the program may use “FART” to impress its family audience. There was already a euphemism for the word in the manual. The system Variable RASP is short for RASPBERRY which is cockney for RASPBERRY TART. See the Spectrum source code

Among its eleven thousand word vocabulary the Scrabble game has the word FART. 💨

In the ZX Spectrum source code, courtesy of Timex, the System Variable 23608 is FART and Steven reveals the Spectrum blows a raspberry when things go wrong. e.g. hold the key T for RANDOMIZE which causes the screen to fill with text until, lacking room, the computer emits a warning buzz.
This is a private joke for his parents and James Hardy Wilkinson who were head hunted to work for Alan Turing in 1946.
During a demo for the Daily Mirror the reporter Ruggles asked what happens when a mistake occurs. Jim replied that it makes a noise like a raspberry. “After all it is almost human”.

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Geoff Wearmouth @warmtoffee.bsky.social · 17/09/2026

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Ken Shirriff @righto.com · 12/09/2026

In 1980, Intel introduced the 8087 floating-point coprocessor chip. Plugging this chip into your IBM PC made math 100 times faster, good for CAD and spreadsheets. I opened up the chip to reverse-engineer exactly how it does complicated calculations. Let's take a look inside...

The integrated circuit is a black ceramic rectangle with 40 metal pins sticking out, in two rows. (This is known as a DIP, a Dual Inline Package.) It has three rows of text: "D8087-1", a cryptic version label, and then the copyright line with a big lower-case I, INTEL m c 1980 1984. The m and c are in circles for the mask-work symbol and the copyright symbol. The chip has a small semicircular notch on the left side, indicating its orientation. The package consists of two thin ceramic layers, bonded together with a gray substance; the metal pins stick out from this gray substance. The ceramic package is important to me because tapping the gray layer with a chisel will cause the two layers to separate, revealing the silicon die inside. In contrast, most chips are in epoxy packages, which are very difficult to open, usually requiring strong acids.

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ZXVintage @zxvintage.bsky.social · 08/09/2026

Popular Computing Weekly cover (9/9/1982) READ: archive.org/stream/NH2021_Popular_C…

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L Break Into Program @breakintoprogram.co.uk · 08/09/2026

The ZX81's native resolution of 64x48 suits big bold graphics, like 3D Monster Maze and Mazogs. This is another good example where the developers have leaned into the limitations. Surprised I've not come across this before. As ever, great video review by @villordsutch.bsky.social

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Geoff Wearmouth @warmtoffee.bsky.social · 05/09/2026

On Page 7 an interview with Richard Altwasser and Steven Vickers about the genesis of the Jupiter Ace and on the previous page a letter about an error in the ZX81 manual (edition 1 only).

The ZX81 manual, edition 1, where the character 135 should be the inverse of what is printed. Fixed in other editions and the TS1000.

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Reposted by Geoff Wearmouth

ZXVintage @zxvintage.bsky.social · 04/09/2026

Popular Computing Weekly (16/9/1982) - The Winged Avenger review READ: archive.org/stream/NH2021_Popular_C…

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Geoff Wearmouth @warmtoffee.bsky.social · 01/09/2026

As the Sinclair advert says, your new ZX80 may qualify as a business expense so you can get the VAT back off the taxman.

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Geoff Wearmouth @warmtoffee.bsky.social · 31/08/2026

A FREE Sinclair ZX81 with a copier purchase. Ends July 1981 so possibly with the first imperfect ROM.

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Sinclair Research @sinclairresearch.bsky.social · 24/08/2026

Spectrum Computing is a remarkable community project - a searchable database of over 30,000 ZX Spectrum titles built on ZXDB by Einar Saukas. Every game, utility, demo, and type-in for the Speccy, catalogued and preserved in one place.

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kevin-palser.bsky.social @kevin-palser.bsky.social · 22/08/2026

Earlier this week screen magnifying was added to the #ZX80 / #ZX81 watchOS app. Also its watch CPU usage was dramatically reduced by 30 to 50%. apps.apple.com/gb/app/zx81/...

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Geoff Wearmouth @warmtoffee.bsky.social · 19/08/2026

On Page 7, a ding-dong between John Lettice, (Personal Computing News) and Boris Allan (Popular Computing Weekly)

John Lettice founder of The Register and author of Turbocharge Your ZX Spectrum

Boris Allan a regular columnist in Popular Computing Weekly and author of many books including this Pitman Pocket Guide

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Geoff Wearmouth @warmtoffee.bsky.social · 14/08/2026

Andrew Pennell produced a map of the Shadow Roms on Page 27. My screen-resident disassembler can analyse Interface1s if you use CLS# before loading. Just select ROM4 by pressing ‘R’ and ‘4’ and then the HEX address from Andrew’s map. It is called ‘utility3’ and available from spectrum computing.

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Geoff Wearmouth @warmtoffee.bsky.social · 21/12/2025

My demon site and email are long gone but most of the ZX Spectrum site is preserved on the Wayback Machine. Download the ZX ROM Collection for the files listed. web.archive.org/web/20150602...

Change txt suffix to asm.
The sc01 files are a whimsy and not worth looking at.
The disassembler in u3.asm is by John Kerr of Glasgow and was serialized in Personal Computer World.
The sg81 source code can be read on the web page.
Have fun.

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Sinclair Research @sinclairresearch.bsky.social · 12/08/2026

Kinda funny when you think how Sinclair made watches back in the day! apps.apple.com/app/id118011...

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kevin-palser.bsky.social @kevin-palser.bsky.social · 11/08/2026

#ZX81 on an Apple Watch. To be crystal clear, no one was daft enough to request this. apps.apple.com/gb/app/zx81/...

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Geoff Wearmouth @warmtoffee.bsky.social · 11/08/2026

On Page 7, a letter from Paul Harrison detailing the cursor in the editing line bug. It featured in Dr. Logan’s book “Understanding Your Spectrum” and also my ZX Spectrum Assembly listing preserved 105 times on the Wayback Machine.

Paul Harrison’s letter explaining how the cursor can appear in the editing line.

The appendix of Doctor Logan’s book crediting Paul Harrison with the discovery.

The cover of the Melbourne House book that mentions Paul Harrison.

My archived ZX Spectrum ROM assembly listing that credits Paul Harrison with the discovery.

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Reposted by Geoff Wearmouth

ZXVintage @zxvintage.bsky.social · 11/08/2026

Your Spectrum (Sep 1985) - New ROM Antics READ: archive.org/stream/your-spectrum-ma…

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Geoff Wearmouth @warmtoffee.bsky.social · 06/08/2026

On Page 5, The ZX Spectrum Team deal their Ace - A Forth-based Jupiter Ace with 48K of RAM, colour and a ZX Printer adapter. If only…

A picture of ZX Spectrum and Jupiter Ace designers who were about to launch an inexpensive Forth computer.
It will be manufactured close to where they live at Bury St. Edmunds east of Cambridge.

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Geoff Wearmouth @warmtoffee.bsky.social · 05/08/2026

John Harris also did the cover of this ZX81 programming book by Ian Stewart and Robin Jones. I love his work. It is the age we are entering now.

The cover of a ZX81 BASIC programming book designed by John Harris showing one of the jets that appears on top of the building on the Sinclair ZX81 manual.

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Sinclair Research @sinclairresearch.bsky.social · 30/07/2026

The prototype ZX Spectrum ROM actually has MORE bugs than the production version. Nine Tiles was busy cramming in new I/O features rather than fixing issues - a true work in progress. www.spectrumforeveryone.com/technic…

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Geoff Wearmouth @warmtoffee.bsky.social · 04/08/2026

Both look nice. I tried the C64 screen

A simple recursive GOSUB test stops after twenty four attempts. ZX Spectrum about fourteen thousand.

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Geoff Wearmouth @warmtoffee.bsky.social · 04/08/2026

The ZX Spectrum could use its entire user memory 41K for a GOSUB stack whereas other 8bits like Commodore, Apple, TRS80 and Microsoft had a 256 byte stack which was shared with FOR/NEXTs and expression space. They were faster but don’t try anything complex like recursion or strings longer than 256.🙂

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Geoff Wearmouth @warmtoffee.bsky.social · 30/07/2026

To confuse further, SYMBOL SHIFT has BASIC keywords and EXTENDED MODE had symbols 🙂

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kevin-palser.bsky.social @kevin-palser.bsky.social · 26/07/2026

#ZX81 apps.apple.com/gb/app/zx81/...

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Geoff Wearmouth @warmtoffee.bsky.social · 17/07/2026

On this occasion it was Bob Maunder of Linsac who had an MSc in Computer Science from Birmingham University. Page 103. datassette.s3.us-west-004.backblazeb2.com/livros/the_z...

datassette.s3.us-west-004.backblazeb2.com

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Geoff Wearmouth @warmtoffee.bsky.social · 16/07/2026

This is the Z80 source code for the ZX Spectrum 16K ROM 1982. The code was written by Steven Vickers and John Grant of Nine Tiles on the Zilog Development System. Hit the red button and enjoy a good read for a computer that is still being made today. www.timexsinclair.com/document/zx-...

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Sinclair Research @sinclairresearch.bsky.social · 16/07/2026

Make sure to check out the amazing iOS ZX81 app! Recent updates are faster, better, stronger. apps.apple.com/us/app/zx81/...

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kevin-palser.bsky.social @kevin-palser.bsky.social · 16/07/2026

To quote @warmtoffee.bsky.social, “An 8K ROM on a par with the 32K ROMs.” #ZX81 apps.apple.com/gb/app/zx81/...

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Geoff Wearmouth @warmtoffee.bsky.social · 15/07/2026

Because it is Dr. Ian Logan who received a prize for technical writing at the end of a computer show. Most manufacturers took legal action against anybody revealing how computers worked back then. Although a good mathematician, he had a surgery full of patients too. Well deserved award.

Dr. Ian Logan after receiving an award for technical writing, mainly descriptions of the ZX80, ZX81 and ZX Spectrum ROMs.

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Geoff Wearmouth @warmtoffee.bsky.social · 15/07/2026

I remember it well. I posted this description of my computer to usenet on 20th August 2015. Guess the model. 🙂

The light colors computer
with full memory was made by an uncle man and some student types way back then.
With a single key it could accept do words and other presses made sense too.
It was a good idea to save this stuff before running
You could buy stuff to put in it though it took time.
Crazy rock man or something. Break out was free.
There was a write thing that worked with funny paper.
There were only four lines of keys so simple.
You had to join it to the tv to see stuff .
They made a lot of them in black but only one white one.
The uncle man got that one.
I still have my first one and the do it this way book. Sigh.

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Theo Sanderson @theo.io · 15/07/2026

13 years ago - how time flies!

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Geoff Wearmouth @warmtoffee.bsky.social · 06/07/2026

And now Sky has bought ITV. Empire building on free-to-air UK media.

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Anthony Barnett @anthonybarnett.bsky.social · 30/06/2026

Very sorry to learn that the magnificent David Potter died on Sunday evening. A pioneering mathematical physicist, he founded Psion, created the first hand-held organizer and oversaw Symbian, the standard mobile operating system. He was a wonderful philanthropist and supporter of @opendemocracy.net

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kevin-palser.bsky.social @kevin-palser.bsky.social · 05/07/2026

#ZX81 With the infinite patience of Claude, the load on the host device has been slashed. Next stop will be adding the latest ROM by @warmtoffee.bsky.social.

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Geoff Wearmouth @warmtoffee.bsky.social · 04/07/2026

On Page 25 an informative FP program from S McCarthy. I uploaded this to Spectrum Computing. Beware the to_power function does not work for all powers of 2 and reciprocals. Vickers indicated in the source that it should start in integer. Not allowed 🚫 spectrumcomputing.co.uk/entry/40367/...

spectrumcomputing.co.uk

Floating Point Numbers - Spectrum Computing

Floating Point Numbers for ZX-Spectrum 48K (?)

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Geoff Wearmouth @warmtoffee.bsky.social · 04/07/2026

On Page 13, John Lettice, founder of The Register magazine, reviews a modem for the ZX Spectrum. This internet malarky will never catch on.

Although labelled QL, this modem is for the ZX Spectrum.

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